Bug fix meta-wrapping tpl-generated attribute keys.

* Wikitext of the form: "<div st{{echo|yle}}='color:red'>foo</div>"
  where an attribute key expands to an array of tokens with one
  part of it coming from a template/extension wasn't being handled
  correctly.  In this example, the property of the meta-tag was
  "mw:objectAttrKey#st,yle" instead of "mw:objectAttryKey#style"

  In RT testing, this kind of wikitext crashed some pages. In reality,
  this kind of wikitext is rare and is usually a result of misparses
  when the source wikitext is buggy.

  For example, the wikitext below is found on en:Croatian Parliament
  The tokenizer thinks this is a tr with a lot of diff attributes and
  and runs into trouble. The fix in this patch prevents the page from
  crashing.

  "|-| colspan=5| Source: Parliament of Croatia<ref name="Previous-Speakers"/><ref name="Speaker-Current"/>"

* Fixes crashers on a few different pages (which probably all have
  buggy wikitext in table tr tags).

  - en:Croatian Parliament
  - en:Crime Scene Unit

* No change in parser tests (TODO: Add the example wikitext at the
  top as a new test).

Change-Id: Idac4d6d9b3274521e4340ddbce176007ecd9e024